Various sites within the body are difficult to access by minimally invasive means, e.g., in order to take biopsy or other samples, or for delivering materials to the site locally. Tissue sites that include infections of the skin and soft tissue, such as cellulitis, typically cannot be cultured, although tissue biopsy, fine needle aspiration, and blood cultures have been attempted. It is occasionally possible to recover bacteria from such sites by means of fine needle aspiration, with the best recovery in conditions of excess tissue fluid, such as congestive heart failure and kidney disease. When used to aspirate tissue or fluids, by the use of negative pressure, needles tend to entrap tissue, thereby preventing ingress of interstitial fluid. Without the ability to quickly access and sample such sites, however, the corresponding identification of the pathogen, and in turn treatment, are often delayed, or not possible at all. There exists a need for the recovery of samples in such circumstances, including the recovery of bacteria from sites in which no ulceration, abscess pocket, or other drainage site might exist.
On another subject, a wide array of devices have been described for use in delivering fluids and compounds (e.g., molecules) to the body, e.g., by means that include anything from direct inoculation or injection to prolonged infusion. Relatively few of these devices are particularly well suited for the prolonged infusion of large molecules (e.g., macromolecules), particularly to regions of the body that are relatively less accessible to needles and the like.
For instance, Tahlila et al. describe the manner in which arterial gene therapy requires efficient local gene delivery to the cells of the arterial wall (“The Dispatch™ catheter as a delivery tool for arterial gene transfer”, Cardiovascular Research, 33(1):181-187). Various vectors can be used, and can be delivered percutaneously using a host of delivery devices, such as double balloon catheters, hydrogel-coated balloon catheters, porous balloon catheters, and ‘channeled’ balloon catheters.
On yet another subject, catheters have long existed for various applications within the body. Applicant has itself become a world leader in the field of catheters having microporous portions (e.g., in the form of “hollow fibers”), for use in various embodiments. See, for instance, U.S. Pat. Nos. 6,030,358; 6,537,241; 6,942,633; 6,942,634; 7,717,871; and 7,935,092; and U.S. Publication Nos. US-2005-0165342-A1; US-2007-0060834-A1; US-2010-0100061-A1; US-2010-0106140-A1; and US-2010-0286586-A1; the disclosures of each of which are incorporated herein by reference.